This is from a friend of my mother-in-law. This friend asked the neighbor nicely to reduce their light pollution, as she is elderly and likes to see the stars from her yard at night. Here are some pics of the response.

Wisconsin does have a model exterior lighting ordinance. It's a general guideline which may or may not have been adopted by the local municipalities. Here is the pertinent section regarding your lighting problem:

Check with your local town hall to see if it has a lighting ordinance and if it follows the Model Exterior Lighting Ordinance. You can also print out this document and show it to your neighbor and ask them ... very politely ... if they would conform to this ordinance ... since their lights are directly shining into your home. Personally, I'd also offer to buy a suitable light shield ... just to be neighborly.

Attorneys aren't cheap. If a friendly chat with the neighbor gets no positive results (and if the lighting ordnance is not in effect) then a few large mirrors mounted on homemade wooden frames and aimed back directly at the neighbor may make the point.

Uhhh, second thought, maybe not too good of an idea and could cause escalation of the situation. I did seriously consider this with a neighbor though before making a light shield and just living with it until we move late this year.

While I couldn't find the exact ordinance, it seems like a call to their office would get it resolved quickly. Madison is well-known for its application of fines and it appears (from the WI Dark Sky Association) that they do have exterior light pollution ordinances.

Best bet is to call and report it to them. Assuming you guys haven't tried going over and talking to them.

Two wrongs do not make a right; and could very well escalate things into a much worse situation, quickly.

The suggestion of checking out the light ordinance, and see if it applies there, and take steps from there to come to a solution, is the best way to handle situations such as this; if talks with the neighbor has failed.

Do I understand correctly that the spotlight was added after the neighbor was asked nicely to cut down on their outdoor lighting? That is incredibly rude and should be pointed out to the city officials as an unwarranted escalation of the situation. It's equivalent to turning up the volume on a music system when you've been asked politely to turn it down.

If the problem is not resolved then call the local TV stations and ask them to publicize the issue.

what bothers me more than the LP is the apparent increasing intolerance of us
- towards elderly neighbors,
-kids and animals at star parties,
- anything that interfer with our viewing
on multilple threads over the past few months.

I did a little digging and found what I'm assuming are the current Madison, WI city ordinances. Here is the applicable part of the section on external lighting...

Sec. 10.085(3)

(3) General Requirements.

(a) All outdoor lighting fixtures installed and thereafter maintained upon private or public
residential, commercial, industrial and other nonresidential property shall comply with
the following:

1. The maximum allowable light trespass shall be 0.5 horizontal footcandles four
(4) feet above the ground. The point of measurement of this offending light shall
be at any point at the outer wall of an adjacent building occupied for residential
or public use, or at any point greater than 10 feet from the adjacent lot line. This
measurement shall not include any ambient, natural light.

2. All fixtures greater than 1,000 initial lumens (equivalent to 70 watts
incandescent) shall be full cutoff, or shall be shielded or installed so that there is
not a direct line of sight between the light source or its reflection and a point five
(5) feet or higher above the ground at the property boundary. The light source
shall not be of such intensity so as to cause discomfort or annoyance.

From the pictures, I'm willing to bet that entire setup violates the city ordinances like nobody's business. Unfortunately, they have made it your business, but I think you will have the city codes backing up your complaint, should you decide to make it.